The whole idea of the Insider build is to test upcoming game updates. The current incentive is a weekly reward for 1 hour of playing the Insider build. You do not have to report a bug or do anything else in particular.
I believe one of the most important goals of the insider build is to find bugs and report them. Currently insiders are not in incentivized to report bugs. That's why I would like to suggest the idea of "Noble Bugfinder Sails". A special set of sails for the insiders that reported an unknown bug. This way you incentivize insiders to report the bugs they encountered. This would make insiders more eager to actively look for bugs. Besides that, I think it's an well deserved reward for people that find a unknown bug.
